On Tuesday, September 27, 2016, an en banc panel of the U.S. Court of Appeals for the D.C. Circuit heard nearly seven hours of oral arguments in one of the most significant environmental cases of the year: West Virginia v. EPA, Case No. 15-1363. This case involves more than 100 parties, who have filed dozens of petitions challenging EPA’s Clean Power Plan and its regulation of greenhouse gas emissions from existing power plants. Challengers include 27 States – led by West Virginia and Texas – labor unions, rural electric cooperatives, industry and trade groups, and private companies. Four intervenor briefs and 18 amici curiae briefs have been offered in support of the Clean Power Plan, by parties including 18 States, Washington D.C., utilities and power companies, environmental organizations, and former EPA administrators. Among other things, challengers argue that EPA exceeded its authority under the Section 111(d) of the Clean Air Act by including electricity-shifting measures and “Outside the Fenceline” requirements in the Clean Power Plan.

As we previously reported, in February 2016, the U.S. Supreme Court granted a stay of EPA’s Clean Power Plan. The stay was highly unusual because the case is still before the D.C. Circuit Court, which denied a request for a stay in January 2016. Adding to the unusual nature of this case, the D.C. Circuit, on its own motion, decided to hear the case en banc in the first instance, which is why the full court sat for oral arguments on September 27th. Notably, Judge Merrick Garland did not sit for oral arguments and will likely not take part in any decision, as he has recused himself from all decisions of the D.C. Circuit while he awaits resolution of his appointment by President Obama to the U.S. Supreme Court. The remaining 10 judges in the D.C. Circuit, Judges Henderson, Rogers, Tatel, Brown, Griffith, Kavanaugh, Srinivasan, Millett, Pillard, Wilkins, took part in the oral arguments.

EPA’s defense of the Clean Power Plan went well during the oral arguments, with apparent support from the D.C. Circuit’s six democrat-appointed judges. The D.C. Circuit will likely expedite its decision in this widely-followed case, with an opinion expected in late 2016 or early 2017. Regardless of the outcome in the D.C. Circuit, the case will almost certainly be appealed to the U.S. Supreme Court for final resolution.